I’m using the “MB85RC.class.nut:1.0.0” library to access the MB85RC1MT 128k x 8 FRAM chip. I am having trouble writing data beyond address 64k (16 bits). Everything works fine below 64k, but I can’t access the upper half of the chip’s memory.
After a closer look at the data sheet, this version of the MB85RC chip series is slightly different. First off, it only has two external address pins (A1 and A2) so only four chips can be on the same I2C bus. Along with that, the 17th address bit is buried in the device address word. What that means is that in order to get to the upper half of the memory, you need to use the successive I2C address. So for A1 and A2 equal 0, the lower half of the chip is addressed at A0 and the upper half of the chip is addressed at A2.
I don’t think the “MB85RC.class.nut:1.0.0” library takes that into account, after reviewing the code on GitHub. Is that why I’m having trouble?